1. Field of the Invention
The present invention relates to a tire vulcanizing system.
2. Description of the Related Art
In a conventional fully automatic tire vulcanizing press, the work time for loading and shaping a green tire and for unloading a vulcanized tire is far shorter than the time over which vulcanization is performed by introducing a heating/pressurizing medium in a tire in a state in which a tire mold assembly is closed. Therefore, a tire mold opening/closing device for opening/closing the tire mold assembly to loading/unloading a tire after the completion of vulcanization and a tire loading/unloading device are law in operation efficiency.
To solve this problem, the applicant of this invention has already proposed a tire vulcanizing system disclosed in Japanese Patent Provisional Publication No. 7-80846 (No. 80846/1995). This tire vulcanizing system comprises vulcanizing stations a1 and a2, mold opening/closing stations b1 and b2, tire mold transporters c1 and c2, rails d for the tire mold transporters, mold beds e1 to e3, tire mold opening/closing devices f1 and f2, unloaders g1 and g2, loaders h1 and h2, conveyors i1 and i2 for conveying vulcanized tires, racks J1 and J2 for green tires, and a mold changing table (a mold changing table for changing a tread mold, side wall mold, etc. in a tire mold assembly to accommodate a change of specification of a tire to be vulcanized and for changing a bladder, which is an expendable) k.
The following is a description of a tire vulcanizing process using a tire vulcanizing system having the above-described configuration.
First, a tire mold assembly M for which vulcanization has been finished is received by the tire mold transporter c1 from the vulcanizing station a1 (or a2) at which a plurality of tire mold assemblies M being vulcanized are arranged, and is transported to the mold opening/closing station b1. Then, after the tire mold assembly M having transported to the mold opening/closing station b1 is connected to the tire mold opening/closing device f1, the tire mold assembly M is opened by the tire mold opening/closing device f1, and a vulcanized tire is unloaded by the unloader g1 attached to the tire mold opening/closing device f1. Next, a green tire is loaded, by using a loader h1 attached to the tire mold opening/closing device f1, into the tire mold assembly M from which the vulcanized tire has been unloaded. Subsequently, after the loaded tire is shaped during a tire mold closing step and the tire mold assembly M is closed, a heating/pressurizing medium is introduced and sealed in the tire, by which a tire vulcanizing step is started. Then, the tire mold assembly M in which vulcanization has been started is disconnected from the tire mold opening/closing device f1, placed on the tire mold transporter c1 again and transported, and returned to the vulcanizing station a1.
When the above-described tire vulcanizing system is applied to a tire production facility whose vulcanization time is as short as, for example, 8 to 10 minutes, the following requirements are encountered.
(1) The time over which the mold transporter receives a tire mold assembly at the vulcanizing station, the work at the mold opening/closing station is finished, and again, the closed tire mold assembly is transported and returned to the vulcanizing station must be made as short as possible. This is because the number of tire mold assemblies constituting the tire vulcanizing system cannot be increased from the economical viewpoint.
(2) From the viewpoint of operation control in which a tire mold assembly having been used out during the operation is carried out, or a new tire mold assembly is put in during system operation in place of the carried-out tire mold assembly, it is preferable that the transportation time for each of the tire mold assemblies arranged in several numbers be made equal. Specifically, it is preferable that the transportation time for a tire mold assembly close to the mold opening/closing station be approximately equal to that for a tire mold assembly distant from the mold opening/closing station.
(3) After the mold is closed at the mold opening/closing station, the heating/pressurizing medium introduced in the tire is temporarily sealed in the tire mold assembly during the transportation, and the heating/pressurizing medium is supplied again after the tire mold assembly arrives at the vulcanizing station. Here, considering the quality control of tire, the time of temporary sealing should preferably short.
(4) When tires are continuously produced by using the tire vulcanizing system, green tires must be supplied continuously. For this purpose, it is necessary to store the most possible green tires in the vicinity of the loader disposed at the mold opening/closing station, and to supply new green tires successively.
Therefore, it has been desired to provide a tire vulcanizing system having the following features: (1) The time taken for the tire mold assembly to be returned to the vulcanizing station can be shortened, and the transportation time for a tire mold assembly close to the mold opening/closing station and that for a tire mold assembly distant from the mold opening/closing station can be made approximately equal to each other. (2) The time for the heating/pressurizing medium to be sealed temporarily in the tire mold assembly can be shortened. (3) The most possible green tires can be stored in the vicinity of the loader disposed at the mold opening/closing station, and new green tires can be supplied successively, by which the installation area can be reduced significantly.
To solve the above problem, the applicant of this invention has proposed a tire vulcanizing system disclosed in Japanese Patent Provisional Publication No. 8-164528 (No. 164528/1996). The operation of this tire vulcanization system is as described below. As shown in FIG. 5, first, at least two tire mold assemblies m (m1,m4, m7) are stacked on a storage rack at a vulcanizing station 800, and a mold opening/closing device 910 at a mold opening/closing station 900 is moved along the storage rack at the vulcanizing station 800. Next, the tire mold assembly m is removed from the vulcanizing station 800, and after the opening/closing of the tire mold assembly m, the unloading of a vulcanized tire t, and the loading of a green tire gt are performed, the tire mold assembly m is returned to the vulcanizing station 800.
However, in this tire vulcanizing system, since the vulcanizing station 800 is tall, a supply apparatus for green tires gt and a delivery apparatus for vulcanized tires t cannot be disposed over the vulcanizing station 800, and these apparatuses must be disposed concentratedly on the opposite side of the vulcanizing station 800 at which the tire mold assemblies are stacked.
Accordingly, an object of the present invention is to provide a tire vulcanizing system which can easily be arranged in an existing tire factory by arranging vulcanizing stations, the height of which is decreased, on a plane on the opposite sides of a movable tire mold opening/closing device, and by making spaces over the vulcanizing stations on both sides capable of being used for a green tire supply apparatus and a vulcanized tire delivery apparatus.
To achieve the above object, the tire vulcanizing system in accordance with one mode of the present invention has a vulcanizing station for mounting a plurality of sets of tire mold assemblies in parallel on a flat surface of a predetermined height and a tire mold opening/closing station formed along the vulcanizing station, and is characterized in that a tire mold opening/closing device, which is movable along the vulcanizing station, takes out the tire mold assembly from the vulcanizing station, and opens and closes the tire mold assembly, is provided at the tire mold opening/closing station, and the tire mold opening/closing device is provided with an upper movable plate capable of elevating an upper mold of the tire mold assembly by connecting with the upper mold, a horizontal transfer device for transferring the tire mold assembly on the same level as the height of the flat surface, and a lower fixed plate capable of fixing a lower mold of the tire mold assembly.
Also, the tire vulcanizing system in accordance with another mode of the present invention further has an unloader, which is movable integrally with the tire mold opening/closing device, for unloading a vulcanized tire, and a loader for loading a green tire.
The above-described tire vulcanizing system has the vulcanizing stations and the tire mold opening/closing station, and the tire mold opening/closing station is provided with the tire mold opening/closing device. The tire mold opening/closing device, which moves along the vulcanizing station, takes out the tire mold assembly stored at the vulcanizing station, unloads the vulcanized tire in the tire mold assembly, loads a green tire in place of the vulcanized tire, and then returns the tire mold assembly to the vulcanizing station. Thereby, the time taken for the tire mold assembly to be returned to the vulcanizing station can be shortened, so that the quality control of tire can be carried out easily.
For the tire vulcanizing system in accordance with the present invention, as described above, the vulcanizing stations are arranged on a plane, and the tire mold opening/closing device is moved along the vulcanizing station to take out the tire mold assembly from the vulcanizing station, to perform the opening/closing of the tire mold assembly, the unloading of the vulcanized tire, and the loading of a green tire, and then to return the tire mold assembly to the vulcanizing station. Therefore, the time taken for the tire mold assembly to be returned to the vulcanizing station can be shortened, and the transportation time for a tire mold assembly close to the tire mold opening/closing device can be made approximately equal to that for a tire mold assembly distant from the tire mold opening/closing device. Also, the time over which the heating/pressurizing medium is temporarily sealed in the tire mold assembly can be shortened, so that the quality control of tire can be carried out easily.